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Here's the poop on your pool water

Germy water caused 90 separate outbreaks of illness that killed one person and put nearly 1,800 into the hospital in 2011 and 2012.
/ Source: NBC News

Germy pool, lake and hot tub water caused 90 separate outbreaks of illness that killed one person and put nearly 1,800 into the hospital in 2011 and 2012, a new report finds.

Most were caused by bacteria and parasites found in human poop, the Centers for Disease Control and Prevention finds in its report. The No. 1 culprit is a germ called Cryptosporidium, which isn’t easily killed by standard pool disinfectants.

“Cryptosporidium comes from swimmers. It is swimmers with diarrhea bringing it into the pool,” said Michele Hlavsa, chief of the Centers for Disease Control and Prevention’s Healthy Swimming Program.

Health officials only started reporting on diseases related to recreational water in 2010. Hlavsa and colleagues collected data for 2011 and 2012, the most recent available, and found that despite chlorination and other disinfecting methods, waterborne illness is common.

“For 2011–2012, the most recent years for which finalized data were available, public health officials from 32 states and Puerto Rico reported 90 recreational water–associated outbreaks to CDC’s Waterborne Disease and Outbreak Surveillance System,” they wrote in the CDC’s weekly report on disease.

These are outbreaks, Hlavsa stresses – not single cases of illness, which would bring the total far higher.

“The 90 outbreaks resulted in at least 1,788 cases, 95 hospitalizations, and one death,” the report adds.

More than half were caused by Cryptosporidium, a diarrhea-causing parasite. Another one-third were caused by Escherichia coli or E. coli. The one death was caused by Legionnaire’s disease, a respiratory illness spread by water, Hlavsa said.

And most outbreaks started in pools, spas or other supposedly treated sources, the CDC found. Fewer than a quarter of the outbreaks started in untreated water such as lakes.

Hotel pools and hot tubs are a common source of the outbreaks, the CDC team found. Nearly 20 percent of outbreaks caused by treated water were linked to a hotel or motel, and most were tracked to spas and hot tubs.

What makes your eyes red in the pool? Hint: It's not chlorine

Interestingly, none of the outbreaks were traced to pee. Urine doesn’t carry germs as frequently as feces does, Hlavsa said. Most of the sicknesses were likely to do “diarrheal incidents” in the water, she said. And the data does not include cases such as the 2013 death of a 4-year-old boy caused by the Naegleria fowleri brain parasite.

Here’s the CDC’s advice:

  • Keep the pee, poop, sweat, and dirt out of the water!
  • Don’t swim if you have diarrhea.
  • Shower before you get in the water.
  • Don’t pee or poop in the water.
  • Don’t swallow the water.
  • Every hour—everyone out!
  • Take kids on bathroom breaks
  • Check diapers, and change them in a bathroom or diaper-changing area to keep germs away from the water.